Grappling tool



April 24, D W OSMUN GRAPPLING TOOL Filed Sept. 14, 1954 n um. om W n a e 0 L w Zi Z United States Patent grappling feel te reihove the s me, t'iit'o'fily a few iniies of the bjt r 1n position to be' engaged by the tool ltoefeet a onnc'tion bywhieh a pnll e be [exerted on the object sueit to riiiv it from the w'ell.A Y

Grapplingtols of the tvrsiiot type, as lir'eifie c iiioilly eonstr'iicted, have been provided with a' cylindrical bowl in which a grapple element orbsheft is posi ed to' grippiiigly engage the exterior ofthe object when 'positioried about thesame and which is [so lbat'd that the end fof the object must extendinto the bowl fora slib; stanti'al distance before it can b e engaged witljrthedjas l't. Freqiiei'itly such tools are also' provided with tubular guides iO'f Substantial length 'al'. their lower ends positioned 40 'easily telescoped over tile object'yh The present invention has for an important V i'nb'ject' v the provision' of a 'grapplingto ofthe short eaten oversiiot type having gripping means which is ciistrilc'ted `and positioned to form an effective Vgripping por neetion with zi portion of a stock bjeiit of Very limited length whereby a pull may b e exerted on the object. Another object of the invention is to' provide a' grape pli'ng tool of the short c'at'ehv eircnlating` 'overshottype hai/iig seht iehhihg hi'eaiis which isehgfigeebie the l iiteribr of a Strick well pipefand with 'the interior vof Athe liowlf tl'ie grappie to form a fhiid tight' seal wii'rebyei'r- Culation of 'uid may. be carried on during'the pulling operation. A

Y'further object of the invention is the provision of a 55 grappling tool of the 'shoi-t 'catch 'oversht type vwliieli embodies 'guide means positioned to engage tire 'Strick object to aid `in the teles'eopiiig of tlie giappl over the bjeet, ,and whose length doe's'vrio siibstant'illy' in'erease the length of the objectwhiel'ims be t. leif'f grip'- prig lengagement lwith the tool; A further object of the invention is to provide a grape pling tool of theshort catch overshottype having a tubular bowl providedI with aii ins'iie dwnwdly tapering seat and an expansibl tiiblar grapple iii the bowl having an external downwardly tapering face conforming to the seat and engageable therewith to contract the grapple into gripping engagement with a stuck object upon relative longitudinal movement of the grapple and bowl.

Another object of the invention is the provision of a grappling tool of the short catch overshot type having a bowl and grapple structure of the kind described and also spiifal forming a do 2,743,130 Patented Api. 24, e

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2 hayihg guide rheaiis eh the hwrwhieh ie ehggebie with aemek ehjeet te guide iheebje'ef )reihe grapple aria whiehiepesifiehed for eiiigageiiie w fh the graphie@ iiihii dhw'iiweid movement ef graphie feifive ie the BGM Y p *A u further" hhjeei ef iheiiive is' te lpi'eyiie e Figure f2 rea ereisifieeiishe view, reken airing `thel iiiie l Figure 3 is a side elevational view ieiitf the tool. Referr'ig now to the drawings in` greater detail, wherein like `niimralsy 'of' referente' d sigiiate die saine 'parte thtig'lfioit the several views, tii numeral c lesigiiatesY a tubular coupling member whose tippei eiid is internally threaded to' reeive'th lwl" eniZK 0f i operating sirihg f eipe which ehren-is' upwardly hij the gieiihd shi ieee. Thee'eupiihg-ihehihei has in eiieihiuy ieduejed lower" end portion which is eiteally thaded for 1 eehheeiieh te the uppei ihfeihiiry `ihieedeii eid'v pertieh trir of iii grapple 'is tooth d ed t 44, for

gripping engagement with the exterior of a wilpp or other stuck object which maybe liteiided int' lie 'rapple Other loiigitiiinl slits :suoli as th'atsliowii at '211, are 'eieerpievied ai eiieu` grapple, whicli teriiilnatevt one end 'inv'vl'rdly f th' nd of tlie grapple and whereby th grapple i's rendered easily' ontr'aeibl and ei'ipaiisliljl' while `at the s'ne time heihg ffhied ih ehe piece. The graphie ihif aleje have ing the end of a stuck object into the grapple.

Above the seat 30 the bowl is formed with an internal upwardly facing shoulder 46, and within the bowl an annular grapple control 48v is positioned in engagement at ef thel grapple' eie its lower end with the shoulder 46 and whose upper end is formed with an internal bevelled end face 50 positioned for engagement with the external bevelled lower end surface 20 of the coupling member 10, whereby the control is retained in position in the bowl. The grapple control has an external annular groove 52, for the reception of suitable packing means, such as the O-ring 54 which forms a fluid tight seal between the control and the bowl. Within the grapple control there is an internal annular groove 56 within which a seal ring 58 is seated in position to form a iluid tight seal between the overshot and the exterior of the stuck object engaged thereby.

At its lower end the grapple control has a downwardly extending key 60 positioned to extendinto the enlarged upper end portion 42 of the slit 40 of the grapple. The key 60 also extends into an internal longitudinal groove or keyway 62 in the bowl, to hold the control and grapple against rotation relative to the bowl.

The tool may be assembled by first inserting the grapple in the upper end of the bowl V16 and screwing the grapple downwardly into position with the downwardly tapering external face 36 thereof in Contact with the internal downwardly tapering seat 30 of the bowl. The grapple control is then inserted in the bowl above the grapple with the key 60 thereof extending into the widened upper end portion 42 of the slit 40 of the grapple and the keyway 62 of the bowl. The bowl may then be connected to the lower end 12 of the tubular string and the tool lowered into the well bore.A

By lowering the tool in the well bore on the string the lower end of the tool may be guided over the object to be pulled which will` be guided into the grapple by engagement with theinternal tapering lower end 'surface 22 of the bowl.` After the grapple has passed over the object it will grip the same, and upon upward movement of the tool, the seat 30 will move upwardly relative to the external face 30 of the grapple, thus contracting rthe grapple into secure gripping engagement with the object so that an upward pull may be takenV on the object to remove the same from the well. It will be apparent that only a very short portion of the upper end of the object need be so located as ,to enter the grapple in order to enable ythe tool to be effectively used to grip the object suiciently to exert an lupward pull thereon.

The ring 26 may extend radially inwardly of the bowl a sufcient distance so that the lower end of the grapple will not pass through the ring when fully contracted and should the upward pull on `the operating string be great enough to result in crushing or distortion of the stuck object and to cause the grapple to collapse, then the lower end of the grapple will engage the ring to prevent the grapple from being pulled downwardly out of the bowl. In the event that a longer portion of the upper end of the object is positioned to enter the tool, the tool may be lowered over the object until it extends upwardly into the control 48 through the seal ring 58, whereupon fluid may be circulated through the string and the object.

Should it be desired to release the tool from the object the tool may be loweredv and when the bowl reaches the limit of its downward movement relative to the grapple the grapple which remains engaged with the object, may expand, and the grapple and bowl may be rotated in an appropriate direction 'to unscrew the threads 44, to thread the grapple off of the object.

It will thus be seen that the invention, constructed and operated in the manner described above provides a grappling tool of the short catch overshot type, which is of simple design and which is readily engageable with stuck objects which are so constructed or positioned that only a few inches of the upper end of the object is available for gripping engagement with the grapple, but which may also be used to connect a tubular string with an object having a longer portion available for such gripping engagement, so that circulation through the string and object may be established.

While the invention has been disclosed herein in connection with a certain specific embodiment of the same, it will be understood that this is intended by way of illustration only, and that various changes in the construction and arrangement of the parts can be made without departing from the spirit of the invention or the scope of the appended claims.

Having thus clearly shown and described the invention, what is claimed as new and desired to secure by Letters Patent is:

l. An overshot to telescope over an object to be withdrawn from a well and comprising a tubular bowl connected to an operating string of pipe and having an inside downwardly and inwardly tapering seat and an inside longitudinal keyway, a tubular expansible grapple in the bowl having a longitudinal side slot and an external downwardly and inwardly tapering face to conform to the contour of, and to rest on said seat, a controlling member in the bowl above the grapple and including a key seated in the keyway and extending into said side slot, and means on the bowl below the seat extending radially inwardly of the inner wall of the bowl in position for endwise abutting engagement with the lower end of the grapple when the grapple is in contracted condition to limit downward movement of the grapple in the bowl.

2. An overshot toY telescope over an object.' to be withdrawn from a well and comprising a tubular howl connected to an operating string of pipe and having an inside downwardly and inwardly tapering seat and an inside longitudinal keyway, said bowl also having an inside tapering lower end face and a counterbore extending inwardly from said face, means in the counterbore having an inside tapering surface forming a continuation of said end face and extending radially inwardly beyond said seat, a tubular expansible grapple in the bowl whose lower end is positioned for engagement with said means to limit downward movement of the grapple in the bowl, said grapple having a longitudinal side slot and an external downwardly and inwardly tapering face to conform to the contour of and rest on said seat, and a controlling member in the bowl above said grapple and including a key seated in the keyway and extending into said side slot in position forengagement with the bowl and grapple to hold the Y bowl and grapple against relative rotation.

3. An overshot to telescope over an object to he withdrawn from a well and comprising a tubular bowl connected to an operating string of pipe and having an inside downwardly and inwardly tapering seat and an inside longitudinal keyway, a tubular expansible grapple in the bowl having a longitudinal side slot and an external downwardly and inwardly tapering face to conform to the contour of, and to rest on said seat, an annular controlling member in the bowl above said grapple and including a key seated in the keyway and extending into said side slot, means in the bowl positioned to engage the exterior of said member and the interior of the bowl to form a uid tight seal between the member and bowl, said member having an inside annular groove and a seal forming element in said groove in position to engage an object extending into said member to form a Huid tight seal between the member and object.

References Cited in the le of this patent UNITED STATES PATENTS 

